This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A087026 #22 Jul 07 2023 21:03:06 %S A087026 77760,1382399778816000,98221093640386560,1053590173895849103360, %T A087026 821095240766161265049600000, %U A087026 511883170649353472639948811682935064652736000,410719109641406326635474611575828305116907342385175347200 %N A087026 Euler's totient of n-th cyclic number. %C A087026 Calculated with Dario Alpern's ECM. %C A087026 Extended using factors of 10^(A001913(n)-1)-1, see Kamada link. %H A087026 Max Alekseyev, <a href="/A087026/b087026.txt">Table of n, a(n) for n = 1..51</a> (first 42 terms from Ray Chandler) %H A087026 Dario A. Alpern, <a href="https://www.alpertron.com.ar/ECM.HTM">Factorization using the Elliptic Curve Method</a>. %H A087026 Makoto Kamada, <a href="https://stdkmd.net/nrr/repunit/">Factorizations of 11...11 (Repunit)</a> %H A087026 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CyclicNumber.html">Cyclic Number</a>. %H A087026 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TotientFunction.html">Totient Function</a>. %F A087026 a(n) = A000010(A004042(n+1)). %Y A087026 Cf. A001913, A087020, A087021, A087022, A087023, A087024, A087025. %K A087026 nonn %O A087026 1,1 %A A087026 _Reinhard Zumkeller_, Jul 30 2003 %E A087026 a(12)-a(42) from _Ray Chandler_, Nov 16 2011